Production of Lactic Acid from Carob, Banana and Sugarcane Lignocellulose Biomass.

Hassan Azaizeh,Augchararat Klongklaew,Joachim Venus,Roland Schneider,Hiba N Abu Tayeh

doi:10.3390/molecules25132956

Abstract

Lignocellulosic biomass from agricultural residues is a promising feedstock for lactic acid (LA) production. The aim of the current study was to investigate the production of LA from different lignocellulosic biomass. The LA production from banana peduncles using strain Bacillus coagulans with yeast extract resulted in 26.6 g LA·L−1, and yield of 0.90 g LA·g−1 sugars. The sugarcane fermentation with yeast extract resulted in 46.5 g LA·L−1, and yield of 0.88 g LA·g−1 sugars. Carob showed that addition of yeast extract resulted in higher productivity of 3.2 g LA·L−1·h−1 compared to without yeast extract where1.95 g LA·L−1·h−1 was obtained. Interestingly, similar LA production was obtained by the end where 54.8 and 51.4 g·L−1 were obtained with and without yeast extract, respectively. A pilot scale of 35 L using carob biomass fermentation without yeast extract resulted in yield of 0.84 g LA·g−1 sugars, and productivity of 2.30 g LA·L−1·h−1 which indicate a very promising process for future industrial production of LA.

Highlights

Lignocellulosic biomass from agricultural crop residues is a promising raw material for lactic acid (LA) production due to its abundant availability, and its utilization can decrease environmental contamination and pollution
The dry matter (DM) of the different lignocellulose biomass of banana, sugarcane and carob used for the LA production ranged between 85.8–93.2% (Table 1)
Our results have shown similar values where the cellulose and hemicelluloses of carob together were 19.35% of the total biomass which mainly consisted of cellulose (Table 1)

Summary

Introduction

Lignocellulosic biomass from agricultural crop residues is a promising raw material for lactic acid (LA) production due to its abundant availability, and its utilization can decrease environmental contamination and pollution. Lignocellulosic biomass is considered a cheap, abundant, and renewable raw material for the production of different by-products such as biofuels, biomolecules, biomaterials, and bioenergy. It represents a more sustainable alternative resource. The bioconversion of lignocellulose to LA is an important alternative for its valorization to produce LA to be utilized in food, cosmetic and pharmaceutical industry [4,5]. Different companies around the world produce about 90% of LA through microbial fermentation of crops (mainly corn) and lignocellulosic biomass [5]. The numerous applications of LA have made it one of the most important products and Molecules 2020, 25, 2956; doi:10.3390/molecules25132956 www.mdpi.com/journal/molecules

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